The distance measuring device which performs distance measurement by the TOF system is known (for example, Japanese Patent Application Laid-Open No. 2008-89346).
In a general structure, such a distance measuring device as described above includes, for example, an imaging element which includes a plurality of pixels of a grid array and makes a stored charge quantity of charges which have been generated in relation to an intensity of incident light readable from the outside in units of pixels, a modulated light emission unit which emits modulated light the intensity of which has been modulated toward an imaging range of the imaging element, a phase difference detection unit which detects a phase difference between emitted modulated light that the modulated light emission unit has emitted and reflected modulated light which has been obtained as a result of incidence of the emitted modulated light which has been reflected from an object for distance measurement within the imaging range upon the pixels of the imaging element on the basis of the stored charge quantity which has been read out of the imaging element in units of the pixels, and a distance measuring unit which measures a distance from the distance measuring device to the object for distance measurement on the basis of the phase difference that the phase difference detection unit has detected.
The phase difference detection unit acquires four pieces of phase information on phases which deviate from one another by every ¼ (90 degrees in phase) of a period of emitted light and derives a phase difference (a phase delay) from, for example, an arctangent formula.
A general imaging element for TOF includes two charge storage parts for one photodiode and acquires phase information on phases which deviate from each other by 180 degrees from the two charge storage parts. Accordingly, in order to simultaneously acquire four pieces of phase information on phases which deviate from one another by 90 degrees, one pixel is configured by two sub pixels (the number of the photodiodes is two) so as to have four charge storage parts in total.
In a related art imaging element to be mounted on the distance measuring device, a first sub pixel and a second sub pixel which detect stored charge quantities in two different storage terms are alternately arrayed one by one in a row direction of the grid array.
On the other hand, there is such a usage status that it is sufficient even when an image dissolution (a minimum size of a distance measurement object distance measurement of which is possible) of the imaging element is low and the imaging element is configured so as to cope with a binning read-out mode. Incidentally, since in the binning read-out mode, the total number of pixels to be processed substantially is reduced, there are such advantages that a required time taken for performing measurement processing is reduced, incident light intensities are averaged and the influence of noise is suppressed.
In Japanese Patent Application Laid-Open No. 2011-530920, Japanese Patent Application Laid-Open No. 2012-19516 or Japanese Patent Application Laid-Open No. 2015-228650, there is disclosed an imaging element which, though not the imaging element to be mounted on the distance measuring device, is mounted on a video filming camera and includes a connection wire for binning. Unlike the imaging element used for distance measurement by the TOF system, in the imaging element for the video filming camera, detection of the stored charge quantities in each of a plurality of terms which are different from one another in start is not requested.
Accordingly, in the imaging element for the video filming camera, each sub pixel has only one charge storage part. In addition, the connection wire for binning is simply wired between the adjacent sub pixels (Japanese Patent Application Laid-Open No. 2011-530920) or is wired between the charge storage parts of each sub pixel for the same color. In addition, in an imaging element for a video filming color camera which is disclosed in Japanese Patent Application Laid-Open No. 2012-19516 or Japanese Patent Application Laid-Open No. 2015-228650, the mutually corresponding sub pixels of the same kind, that is, the sub pixels which detect the light intensity of the same color component of incident light are not continuously arrayed in the row direction or in the column direction of the grid array.
It is desired to connect together the mutual first sub pixels with each other and to connect together the mutual second sub pixels in order to cope with binning. However, in the related art imaging element, in the case where the sub pixels to be objects for wire connection have been connected together, since a sub pixel which is not the object for wire connection is interposed between the sub pixels concerned, the length of the connection wire is increased. An increase in length of the connection wire causes a reduction in aperture ratio.